In the field of telecommunications, there is a trend to reduce both the size and the expenses associated with infrastructure equipment. The result is a demand on telecommunications infrastructure equipment providers to manufacture smaller equipment that can be operated and maintained in a more cost effective manner, while retaining all the functionality of legacy equipment. The modularity of designs proposed for such equipment, along with the smaller sizes desired by system operators, has introduced new thermal management challenges for dissipating heat generated by telecommunications infrastructure equipment.
Cooling fans used in conjunction with heat sinks are one means used for removing heat from equipment cabinets into the surrounding environment. The thermal energy generated from electronics equipment is directed to a heat sink that is either mounted to or an integral part of the equipment cabinet. The heat sink will typically have a plurality of fins exposed to the ambient atmosphere. The fins establish a large surface area that is in contact with the external ambient atmosphere, promoting thermal heat transfer from the heat sink to the atmosphere. The cooling fans establish a continuous stream of forced air through the heat sink fins, which removes the heated air from the proximity of the heat sink and replaces the heated air with relatively cooler air having a greater capacity for absorbing heat. One problem with this approach is that the fans must be continuously running in order to create the forced air circulation over the fins. In some areas, civic officials object to the noise created by such fan operation as a public nuisance. Further, reliability of the enclosed system becomes dependent on keeping the fans running so that electronic equipment does not overheat and fail. Thus the reliability of the system is essentially limited to the mean-time-between-failure (MTBF) ratings of the fans.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for improved systems and methods for equipment cooling.